Where there’s pot, there’s often an insatiable hunger. A new study gives a clue why: Cannabinoids, the drug in marijuana, appear to flip a neural circuit that normally tells us we’re full into thinking we’re hungry.

Last week the U.S. Food and Drug Administration (FDA) approved a new device that aims to curb hunger by zapping a nerve. The device stimulates the vagus nerve and may curb hunger by blocking communication between the stomach and the brain, but researchers still aren’t sure why it makes people feel less hungry.

In a recent article written for Tufts Now several scientists describe a set of useful guidelines to follow when attempting to understand the validity of a diet trend. The faculty members of the Friedman School of Nutrition at Tufts University explain that many dietary claims or fads surface because the message “eat more fruits and vegetables” is boring, and people crave exciting, breakthrough advice. The guidelines for debunking false information are called “10 Red Flags of Junk Science”, and have been developed by the Academy of Nutrition and Dietetics, the American College of Nutrition and the American Society for Nutrition. To read through a description of each guideline check out the Tufts Now article.

When it comes to weight loss there is never a lack of opinions and advice. Many people claim that low-fat diets is the key to losing weight, others say that counting total calories is the only effective measure to take. In a recent opinion article in the New York Times, two scientists attempt to uncover why the type of food you eat, not how much you eat, may be more important in terms of regulating hunger. The claim is that when extra energy from food (in the forms of glucose and fatty acids) is stored in the fat tissue instead of circulating in the blood our brain will tell us to eat more. Therefore, the fatter you get, the more energy the fat tissue takes up and the hungrier we become, leading to a vicious cycle of weight gain. The culprit in all of this? Insulin – the hormone that is released from the pancreas in response to an increase in blood glucose concentrations. Insulin tells fat cells to take in glucose and fatty acids from the blood, so they can either be used for energy or stored for later. The scientists, Dr. Ludwig and Dr. Friedman, state that foods that cause a higher insulin spike will cause more energy to be stored, thereby causing more hunger in the longterm. Foods that are high in processed carbohydrates and simple sugars cause a larger spike in insulin because glucose gets to our bloodstream quicker when foods can be easily digested and absorbed. Foods that contain fiber, protein and fats take longer to digest and absorb, so the entry of glucose into the blood (and subsequent release of insulin) after eating them is slower.

So what do you think, is it total calories or total carbohydrates that should be the focus of weight loss advice? As always, it is important to think critically when it comes to using the advice of others for your own health goals. So go ahead, do your research and decide what a healthy lifestyle looks like for you. To read the full opinion article head to the New York Times.

The world of nutrition has a long way to go before it fully understands the complex relationship between the brain and the gut, but a recently published study seems to have made a significant step in an interesting direction. The study, published the journal Health Psychology, asks the question of whether our beliefs about a particular food change us physically – that is, if you think a food is good (or bad) for you, do we have a different physiological response to that food? To answer this question researchers had study participants drink either a rich, high-calorie milkshake called “Indulgence”, or a more healthy, low-calorie milkshake called “Sensishake”, then measured blood levels of ghrelin – a hormone that signals to the brain that we’re hungry. The trick? Both milkshakes were actually identical, with no difference in ingredients (or calories). Even so, the participants that drank the “Sensishake” had higher levels of ghrelin than those that drank the “Indulgence”, making them feel hungry sooner!

Google has made it even easier to compare two types of foods. Just type the names of those foods versus one another into the search bar (for example: “wheat bread vs white bread”) and the nutrient composition for the two foods will pop up. This side-by-side comparison includes the total calories, macronutrients and micronutrients. There are of course some limitations of the tool, you can only compare two foods at a time for example, and the information may not be completely accurate, but this tool does allow for some quick and easy comparisons. Try it out and see what you discover!

Authoritarian parents are not very affectionate and may have strict rules without explanation. A recent Canadian study has linked this parenting style with a higher risk of obesity in their children. Children of authoritarian parents may be more likely to engage in risky behaviors, including behaviors that can lead to weight gain. These children may be “responding negatively to not being able to question things or discuss things” says one of the study’s authors.

This study is another in an existing set of data that support the idea that the authoritarian parenting study is linked with childhood obesity. Read more about the study here.

You probably already know that nutritional needs change as we grow older. A healthy diet for an infant, teenager and older adult can all differ dramatically since the body is in different stages of growth. A new study highlights one of these dietary differences and how consuming it at different points in your life may actually change overall health: protein. In this study researchers found a correlation between the amount of protein study participants ate and cancer and premature death. In middle aged people, a low protein diet was associated with lower incidence of cancer and overall mortality, but in older aged adults it was the high protein diet that associated with health. Why would protein needs change so much as we grew older? It may be that a certain molecule in our body that triggers growth is not as responsive to protein intake in older age, so we need more protein to activate it. Read more about this study and the explanation at NPR’s coverage here.

The nutrition facts label that we see on the sides of food packages is getting a make-over, after over 20 years of its use. The new labels are meant to be easier to understand for the consumer through changing what is on the label and altering the format. One major change is altering what is considered a serving size, so that it more closely follows what a person actually eats. For example, a bottle of soda or juice is currently labeled as 2 1/2 servings, so the consumer has to multiply the calories by 2.5 to determine how many calories and added sugars are actually contained in the bottle. Under the new guidelines, food products that are commonly consumed in one sitting will be listed as one serving. Some other important changes reflect research findings over the past decades, including research on vitamin D. It has recently been reported that a large portion of the U.S. population is deficient in vitamin D, therefore the new Nutrition Facts label will require food companies to list the amount of vitamin D in their product. So what do you think? Is the label more user-friendly? Read about the changes and view an example of the label at the FDA’s press release here.

Vitamins are essential nutrients that are required for the function of several proteins in our body. If we become deficient in one or more vitamin entire cellular processes will shut down, leading to sometimes deadly diseases like scurvy, beriberi and pellagra. The body has developed intricate systems to ensure that vitamins are absorbed and stored correctly, preventing deficiency if we go too long without eating our fruits and vegetables. While vitamin storage is helpful, have you ever stopped to think about why the human body requires consumption of specific nutrients in the first place? After all, several other mammals can make many of the vitamins that we must eat. At some point in human evolution the genes that are needed to synthesize vitamins have been silenced or lost. A report from The New York Times looks at this relationship between human evolution and food consumption.

A study has found that organic milk may contain a better balance of omega-3 and omega-6 fatty acids than conventional milk. Both types of fatty acids are essential, but it is the omega-3 fatty acids that may have beneficial health effects, like preventing heart disease and lowering inflammation. The typical western diet is low in omega-3 fatty acids, which are found in oily fish and some nuts and seeds, like flaxseed. Claims that pasture raised meats and animal products contain larger concentrations of omega-3 fatty acids compared to grain-fed animals have been made, but this study published in PLoS One is the most clear example to date. In the study, samples of organic and conventional whole fat milk sourced from around the country were analyzed. Organic milk was found to contain 62 percent more omega-3 and 25 percent less omega-6 fatty acids than conventional milk. The study’s authors conclude that drinking the recommended servings of organic whole milk everyday would improve the ratio of omega-3 and omega-6 fatty acids in the blood, decreasing heart disease risk.

To read more about this study, as well as about why some prominent nutrition scientists question the conclusions of this study check out the article at The New York Times.

The anti-bacterial resistant superbug MRSA has been documented in the U.S. food supply, but until recently other countries have yet to find the superbug in their food. Unfortunately MRSA has recently shown up on a poultry farm in the U.K., which may be the first sign that MRSA is taking over the U.K.’s meat industry as well.

Overuse of antibiotics in the food supply is blamed for the development of the resistant strain of bacteria. Constant exposure to antibiotics kills off the strains of bacteria that are affected by the drug, leaving the stronger, resistant strains to take over. These resistant strains can spread from livestock to humans working with the animals either at the farm or at the slaughterhouse, causing a risk for human disease. Some bacteria can also travel to produce growing nearby via migratory animals or irrigation systems. In the U.S., the Food and Drug Administration is attempting, for the first time, to limit the use of antibiotics in meat production. Under the new policy farmers and ranchers are no longer able to use antibiotics to make animals grow larger, a practice that is commonplace today. Farmers and ranchers will now need a prescription from a veterinarian to purchase antibiotics, a large change from the current practice where antibiotics are available for purchase at animal feed stores.

Click here to read more about the MRSA found in the U.K. poultry farm, and here to read about the FDAs decision to restrict antibiotic use in livestock in the United States.

An observational study here at Tufts University has found that a deficiency in vitamin B12 is associated with cognitive decline in older adults, even if that deficiency is mild. Adults over the age of 75 were followed for 8 years, during which time dementia was assessed by screening. The adults that had lower vitamin B12 blood levels were more likely to experience cognitive decline during the 8 years. This is an important finding because older adults have a harder time absorbing vitamin B12 from food, which is found in meats, poultry and eggs. Read more about the study here.

It’s not often that nutrition scientists agree as to whether a food or nutrient is good or bad for you, so when an agreement is met it’s worth paying attention to! Synthetic trans fatty acids are one of those nutrients that nutrition scientists can agree is unhealthy since it can lower the “good” HDL cholesterol and increase the “bad” LDL cholesterol. Due to this overwhelming evidence the Food and Drug Administration has proposed a banning of trans fats in food products, which has the potential of eliminating them from the American diet completely. This new regulation does not come without its criticism however, as some nutritionists and dietitians fear that the real problem in American’s diet is saturated fat. Dr. Scott Grundy, director of the Center for Human Nutrition at the University of Texas Southwestern Medical Center says “In the push to reduce trans fats, people have been forgetting that saturated fats are much worse because there is a lot more saturated fat in the diet than trans fat”. Read more at The New York Times.

Kidney disease is one complication that can arise in people with diabetes. It has previously been posited that the extra blood glucose in diabetes damages the kidney through a toxic molecule called superoxide anion. Research at the University of California, San Diego School of Medicine has recently found that this is not the case. By analyzing the amount of superoxide anion produced in the mitochondria of diabetic mice, researchers have discovered that LOW concentrations of superoxide anion are associated with diabetic kidney disease, and HIGH concentrations of superoxide anion are associated with less markers of diabetic kidney disease. This discovery changes the field of diabetic research, and may lead to better understanding of diabetic kidney disease. Read more about this discovery, as well as possible explanations for how diabetes may cause kidney disease here.

Obesity and type 2 diabetes rates in the U.S. have grown substantially in recent decades, but until recently Eastern cultures have been immune. Unfortunately, many Asian cultures have succumbed to this alarming trend, and now have obesity and diabetes rates that mimic America’s. In China, rates of type 2 diabetes has surpassed rates in the U.S., perhaps due to the movement of Westernized cultureinto China. Many popular U.S. food chains are now present in the Asian superpower, and sedentary desk-jobs are replacing more active laborer positions. Read more about this shift at The New York Times.

To combat the alarming obesity and diabetes trends, the Chinese central government is taking steps to improve the population’s diet through a new nutrition campaign, including dietary monitoring and intervention, as well as guidelines for food producers. Read about the measures being taken by China here.

There is plenty of controversy surrounding the safety and usefulness of food additives and GMOs, or Genetically Modified Organisms. Golden Rice – the rice that is genetically manipulated to contain a precursor to vitamin A – is no exception. Proponents of the GM crop say that bringing Golden Rice to underdeveloped countries can provided a means to prevent blindness and death caused by vitamin A deficiency. Plus Golden Rice is a sustainable intervention, as it can be grown in the countries in need by local farmers. On the other hand, opponents argue that introducing a GM crop is a risky endeavor, as the GM seeds may cross pollinate with “normal” strains of rice, resulting in a local extinction of non-GM rice species. You can read about some of the latest problems the Golden Rice industry has faced in this New York Times article.

What causes obesity? Is it that we are all eating too many calories, or does the food that we eat actually change the way fat is stored in the body? Perhaps changes in the modern environment are to blame, such as chemicals like BPA or the widespread use of lightbulbs at night. Chances are that the obesity epidemic has several causes, and there is not just one simple solution. Read more about this here: The Obesity Era.

The dopamine reward center in your brain is responsible for giving you feelings of pleasure when you do something you like, including eating your favorite foods. A study by Dr. David Ludwig at Boston Children’s Hospital found that foods with a high glycemic index (like processed foods high in sugar) stimulates the reward center, which may lead to food cravings and addiction. Read more at Boston Children’s Hospital’s blog.

It seems that nutrition researchers can never agree when it comes to determining what foods are good and bad for us. Why are there so many conflicting results? A science writer explains what makes nutrition research especially tricky, and how we can know so much about health foods yet obesity rates still skyrocket. Read more at the New York Times: Why Nutrition Is So Confusing

While most doctors’ prescriptions tend to be for drugs, doctors in NYC are starting to write prescriptions for fresh fruits and veggies. The program connects low income patients with local farmer’s markets. The idea being that people fill prescriptions for drugs, why not prescribe healthy food. The program seems to be helping – 38% of participants saw a decreased BMI after participating. Read more at NPR’s coverage: No Bitter Pill: Doctors Prescribe Fruits and Veggies